Electric-arc lamp.



J. G. LINCOLN.

ELEGTRIG ARC LAMP.

APPLICATION FILED JAN. 16, 1905.

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JOHN C. LINCOLN, 0F CLEVELAND, OHIO, ASSIGNOB TO THE LINCOLN COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ELECTRIC-ARC LAMP.

Specification of Letters Patent.

Patented Feb. 15, 1910.

Application filed January 16, 1905. Serial No. 241,193.

To all whom it may concern:

Be it known that I, JOHN C. LINCOLN, a citizen of the United States of America, and a resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

My invention relates to improvements in electric arc lamps, and has for its object, the provision of an arc lamp of extremely simple construction and advantageous operation.

My improvements herein recited are adapted for lamps employed upon direct and alternating circuits employing constant current, or upon constant potential direct current circuits, and are embodied in a structure having a single armature coil prefer: ably supporting directly the upper carbon carrier.

It has long been a recognized factor in the construction of arc lamps, that the friction must be reduced to a minimum, and the lift must be even and practically constant at all vpositions of adjustment for the upper or adjustable carbon. Accordingly, I have sought to adapt my improvements to this end, and have produced a lamp presenting the simplest construction, coupled with high efiiciency and slight liability to get out of order. 1

In the drawings forming a part of this specification, I have illustrated in some detail, the construction of the lamp embodying my present improvements; wherein,

Figure I. is a view of said lamp in elevation; a portion of the laminated field being partially broken away, better to illustrate the operative parts of the lamp. Fig. II. is a vertical section of the lamp. Figs. III. and IV. are transverse sections viewed in o posite directions from the section line'indicated near the top of Fig. II. Fig. V. is aplan View of the movable armature and carbon-carrier. Fig. VI. is a view in elevation of the latter, partially broken away and in section and, Fig. VII. shows a combined series and shunt wound armature, for use in the lamp when the same is employed in constant current circuits.

Throughout the several figures of the drawin s, I have employed the same character 0 reference to designate similar parts; and Figs. III. to VII. are upon a slightly enlar ed scale calculated to bring out certain Features of the improvement.

A crown or cap-piece a. serves as a sup port for the entire lamp, which depends therefrom. The field b. of the lamp is formed of a large number of laminated U- shaped pieces of sheet iron, united in eleven radial groups 6, about the longitudinally slotted central tube 0; the opposing edges of said slot being serrated, as shown in Fig. I, to serve inlieu of any form of dash-pot.

The action thereof will be understood, when it is explained that the hardened steel tooth d, carried upon the armature cl, is of such width as to strike upon the alternatelypositioned teeth of the serrated slot. This serves momentarily to block or check the tendency of the armature to move in either direction, by causing the entire armature to turn slightly back and forth upon its vertical axis, under the influence of said serrated slot. This is explained more in detail, and claimed in a separate co-pending application filed by myself, and requires, as I believe, no further description herein.

A casing c surroundsthe upper portion of the lamp, while a tubular corrugated part unites the upper and lower portions of the lamp, through the medium of suitable insulation. An mclosed-arc globe g, and carbonholder It, will at once be recognized.

Considering now the details of the lamp, it is seen that the laminated field is composed of substantially U-shaped sheet iron punchings radially assembled, and that the upper portions thereofafiord a relatively good path for the magnetic lines, while the lower limbs of said punchings are tapered or interiorly diverged,-so that the magnetic body is reduced in volume, and the air-gap at the lower extremities is at the maximum. In other words, the opening between the limbs of each punching is slightly V-shaped, within which space thus provided in the field, the annular armature d is supported This armature, it should be observed, is of the lightest practicable construction, since weight in this portion of the lam seriously affects the proper adjustment of t e are. Accordingly, I employ-a light brass or aluminium shell or bobbin for the armature, whereon is wound insulated aluminium-wire of as few ampere-turns as is practicable to accomplish the adjustment of since it may be of suflicient size to avoid the are, thereby producing a much lighter armature than by any other construction with which I am acquainted. WVeight for weight, the aluminium wire provides the most des'rable conductor for the armature,

heating, which otherwise would necessitate more or less exposure or radiating surface.

A central tube (5 united with the annular armature, by a fin d serves to receive and support the upper, and movable carbon of the lamp. As best shown in Fig. II, the upper and lower ends of the carbon-holder are provided with flanged rims d", fitting somewhat closely but easily, within the receiving-tube 0; these flanged parts thus steadying and centering the armature and carbon in their respective positions in the lamp.

The corrugated tubular connecting-part f affords a maximum heat-radiating surface, between the burning arc and the operating parts of the lamp, in order to maintain the latter as cool as possible under operative conditions. More than this, the corrugated walls of the connecting-part afford a relatively long path for the conduction of heat between the united parts; providing accordingly, in a relatively small space, means for avoiding the conduction, and for affording the radiation of heat. The connecting-part f interiorly forms a continuation or extension of the tube 0 almost to the inclosing globe, thus permitting the complete descent of the carbon-carrier and upper carbon. Current is supplied to the lamp in Fig. I, from the right hand binding-post through the flexible spiral conductor 2' above the armature, thence through the armature winding to the metallic bobbin thereof, the supported upper carbon and established arc, to the lower carbon; thence by means of the holder 72- and its extension it, to the left hand bindingpost, and resistance 0 diagrammatically shown, all in series relation.

Explanatory of the mode in which the lamp operates, I may say that the current flowing through the windings of the armature produces a field of force, wherein the flux of the magnetic lines through the iron is at a maximum when the coil is at the top of the laminated field, and at a minimum when at the bottom of the gradually diverging limbs thereof. lVithin this tubular magnetized structure, .the light armature and supported carbon tend to move, opposed only by the weight of said parts, but by reason of the construction shown, the gradually diminishing weight is supported by an approximately equivalent pull or lifting effect at all points of adjustment. In the structure shown, the pull decreases with the decrease in weight, as the armature descends between the slightly diverging walls of the field structure; yet the lifting effect circuits. so proportioned as to have an excessive 11fttreme top of the lamp; while the coil in is evenly secured in such manner as to avoid practically all friction, and free the armature and carbon-holder from any cramping action whatsoever. It will at once be appreciated that the air-gap is greatest in the lowest position of adjustment of the armature.

Merely by employing the compound series and shunt armature of Fig. VII. in my improved lamp, the same is adapted for use upon alternating or direct constant current In this armature, the series coil is ing effect, tending to raise itself to the exshunt relation with the arc is opposed to the former, and tends to neutralize the same in the well known manner. As before, aluminium wire and an aluminium bobbin may, with advantage, be employed, thus materially decreasing the weight of this type of armature. I

From the foregoing, it will be readily appreciated that the lamp disclosed is one of extreme simplicity; one that. operates positively, and without liability to become disordered; and one securing other distinct advantages in the operation thereof.

Those conversant with the art, will readily understand the features of construction characteristic of lamps, respectively intended for use with direct and alternating currents, and that such characteristics will be supplied in arc lamps of my improved construction. For example, it need scarcely be pointed out that the complete annulus or bobbin shown in F V., is not suited to armature construction intended for alternating current lamps, because of eddy currents excited therein; and I do not limit myself to this precise construction for supporting the carbon-holder, nor to the particular form of armature. Again, a field-structure of laminated type is not essential in a lamp employed upon direct current circuits, and my invention is not restricted thereto.

Having now set forth the same in its preferred form, and illustrated an arc lamp embodying the features of my invention, I claim as new, and desire to secure by Letters Patent, the following;-

1. In an arc lamp, the combination with a series connected coil or winding, of a carbon-holder for receiving and supporting the adjustable carbon directly from said coil, and a stationary field-structure affording co-acting means for securing a substantially equal pull throughout all positions of adjustment of the armature coil and supported carbon, substantially as set forth.

2. In an arc lamp, the combination with an annular armature coil, of a carbon-holder for receiving the adjustable carbon, directly supported from said coil, and a stationary tubular iron field-structure relatively more 130 massive in its upper portion, whereby the lifting effect of the armature is maintained substantially in proportion to the supported an armature and a carbon-holder for theadjustable carbon of the lamp, connected to be actuated thereby; the said armature being wound with insulated aluminium wire, whereby the weight of said armature is materially decreased, substantially as set forth.

5. In an arc lamp, the combination with a field-structure having divergent walls, of an improved armature and carbon-holder for the adjustable carbon of the lamp, comprising a relatively light bobbin, a carbonholder connected therewith, and a coil or winding of insulated aluminium conductordisposed upon said bobbin, substantially as set forth.

(3. In an arc lamp, the combination with a field-structure having divergent walls, of an improved armature and carbon-holder for the adjustable carbon of the lamp, comprising a sheet metal bobbin, of aluminium, a carbon-holder connected for support there on, and an exciting winding or coil of aluminium wire mounted upon the said bobbin, substantially as set forth.

7. In an arc lamp, the combination with a series connected coil or winding, of a traveling carbon-holder for receiving and carrying the adjustable carbon, the same being directly and wholly supported by said coil, and a field-structure.aifording co-acting means for securing a substantially equal pull throughout the travel of the armature coil and supported carbon, substantially as set forth.

8. In an arc lamp, the combination'with an annular armature coil, of a carbonholder for receiving the adjustable carbon, the

a same being directly and wholly supported from said coil, and ast'ationary tubular iron field-structurerelatively more massive in its upper portion, thereby maintaining the lifting effect of the armature substantially in proportion to the supported weight, substantially as set forth.

In an arc lamp, the combination with a field-structure formed of laminated U- shaped parts, of a central tube about which ,lhe same are radially disposed. an annular armature respectively inclosing and inclosed by the limbs of the laminated field-structure, a carbon,- holder carried thereby, directly supporting the weight of the adjustable carbon, and a co-acting lower carbon-holder depending from the field-structure, substantially as set forth.

10. In an arc lamp, the combination with a field-structure formed of laminated U- shaped iron pnnchings affording a gradually diminishing body of metal from top to bottom, of a central tube about which the same are rad ally disposed, an annular armature respectively inclosin and inclosed'by the limbs of the laminated field-structure, a carbon-holder carried thereby, directly supporting the weight of the adjustable carbon, and a co-acting lower carbon-holder depending from the field-structure, substantially as set forth.

11. In an arc lamp, the combination with an annular armature, of a carbon-holder for the adjustable carbon directly supported thereby, a tubular field-structure having concentric limbs respectively inclosing and inclosed by the annular armature, said limbs being so proportioned as to afford a substantially equal pull at all positions of adjustment for the armature and supported carbon, substantially as set forth.

12. In an arc lamp, an iron field-structurehaving concentric limbs, of a single exciting coil forming the movable armature, a carbon-holder connected therewith for the adjustable carbon of the lamp and wholly supported by the armature, an inclosing globe, and means for damping the movement of the adjustable carbon-holder, substantially as set forth.

13. In an arc lamp, an inclosing iron fieldstructure, a series-connected exciting coil forming the" movable armature therein, a carbon-holder connected therewith for the adjustable carbon of the lamp and wholly supported thereby, a co-acting carbonholder, and means for damping or checking the movement of the adjustable carbonholder, substantially as set forth.

14:. In an arc lamp, the combination with an iron field-structure proportioned to secure substantially an equal field across the movable armature thereof, of an armature mounted therein and provided with windings affording means co-acting with the field-structure for exerting a pull or lifting efl'ect equal to the weight of the moving coil and carbon throughout. all positions of adjustment, and a carbon-holder for the adjustable carbon of the lamp, wholly supported by the said movable mature coil, substantially as set forth.

15. In an arc lamp, the combination with a tubular iron field structure having divergent inclosing outer and inner walls, of an improved armature and carbon-holder for the adjustable carbon of the lamp, comprising a coil or winding of insulated aluminium conductor, a carbon-holder or receptacle for the adjustable carbon of the lamp, and means for connecting said carbon-holder for support by the coil, substantially as set forth.

16. In an electric arc lamp, the combination with a traveling armature coil, of a carbon holder for the adjustable carbon wholly supported thereby, and acooperating iron field structure proportioned to insure substantially constant pull under conditions of constant current supply; said pull being equal to the weight of the armature coil and supported carbon and carbon -holder, substantially as set forth.

17. In a structure'of the class described, the combination with the movable armature coil of a eo-a'cting stationary iron field structure inclosing the same; said field being longitudinally proportioned with varying cross section to exert a substantially constant pull under conditions of constant current supply to the armature, whereby said pull will equal the weight of the coil and connected parts, and a traveling carbon-holder positioned within said field and wholly supported by the armature coil, substantially as set forth.

18. In an arc lamp, the combination with an annular armature coil, of a carbon-holder for receiving the adjustable carbon, the same being wholly and directly supported from said coil, and a stationary tubular iron fieldstructure within which the armature is mounted to travel, the walls of said fieldstructure bein made downwardly divergent, whereby the lifting effect of the armature is maintained substantially in proportion to the supported weight, substantially as set forth.

19. In an arc lamp, the combination with a tubular field-structure having divergent inner and outer limbs, of an annular armature coil respectively inclosing and inclosed by the limbs of said field-structure, wherein the same is adapted to travel, a carbon-holder carried by the armature and wholly supporting the weight of the adjustable carbon, and a co-acting lower carbon-holder, substantially as set forth.

20. In an arc lamp,-the combination with a tubular field-structure having divergent inner and outer limbs, of an annular armature coil respectively inclosing and inclosed by the limbs of said field-structure, wherein the same is adapted to travel, a carbon-holder carried by the armature, the same being ositioned and traveling within the inner imb of the field-structure and wholly supporting theweight of the adjustable carbon, and a co-acting lower carbon-holder, substantially as set forth.

21. In an electric arc lamp, the combination with a stationary tubular iron fieldstructure having divergent inner and outer limbs substantially throughout its length, of an armature coil positioned between the said limbs, a carbon-holder traveling within the said field-structure and wholly supported by the armature coil, whereby the lamp is rendered extremelycompact, and a lower carbon-holder co-acting therewith, substantially as set forth.

Signed at Cleveland, this 14th day of Jan. 1905 in the presence of two subscribing witnesses.

JQHN C. LINCOLN. Witnesses:

PETER M. HITOHCOCK,

LAWRENCE HITCHGOCK. 

